Characteristic of copper matrix simultaneously reinforced with nano- and micro-sized Al{sub 2}O{sub 3} particles

Journal Article · Tue May 15 04:00:00 EDT 2012 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2012.02.022· OSTI ID:22066450

Rajkovic, Viseslava; Bozic, Dusan; Devecerski, Aleksandar; Jovanovic, Milan T

The effect of the simultaneous presence of nano- and micro-sized Al{sub 2}O{sub 3} particles on the microstructure and properties of copper matrix was the object of this study. The mixture of inert gas-atomized prealloyed copper powder (with 1 wt.% Al) and 0.6 wt.% commercial Al{sub 2}O{sub 3} powder (serving as micro-sized particles) was used as the starting materials. Strengthening of the copper matrix was performed by treating the powders in the air for up to 20 h in the planetary ball mill. During milling of the prealloyed powder, finely dispersed nano-sized Al{sub 2}O{sub 3} particles were formed in situ by internal oxidation. The approximate size of these particles was between 30 and 60 nm. The highest values of microhardness were reached in compacts processed from 10 h-milled powders. The microhardness of compact obtained from 10 h-milled powder was 3 times higher than the microhardness of compact processed from as-received and non-milled prealloyed powder. At the maximum microhardness the grain size reaches the smallest value as a result of the synergetic effect of nano- and micro-sized Al{sub 2}O{sub 3} particles. Recrystallization, which occurred during prolonged milling, was the main factor influencing the decrease in microhardness. The increase in electrical conductivity of compacts after 15 h of milling is the result of the decrease in microhardness and activated recrystallization processes. Highlights: Black-Right-Pointing-Pointer Copper matrix was reinforced with nano- and micro-sized Al{sub 2}O{sub 3} particles. Black-Right-Pointing-Pointer The twofold role of coarse Al{sub 2}O{sub 3} particles in matrix strengthening exists. Black-Right-Pointing-Pointer During shorter milling time these particles contribute to increase of microhardness. Black-Right-Pointing-Pointer At longer milling time decrease in microhardness is related to recrystallization.

• OSTI ID: 22066450
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: Complete Vol. 67; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
COPPER
ELECTRIC CONDUCTIVITY
GRAIN SIZE
MATRIX MATERIALS
MICROHARDNESS
MILLING
MIXTURES
NANOSTRUCTURES
OXIDATION
PARTICLES
POWDERS
RECRYSTALLIZATION